Memory Arrays Comprising Strings Of Memory Cells

Embodiments disclosed herein pertain to memory arrays comprising strings of memory cells and to methods used in forming memory circuitry.

Memory is one type of integrated circuitry and is used in computer systems for storing data. Memory may be fabricated in one or more arrays of individual memory cells. Memory cells may be written to, or read from, using digitlines (which may also be referred to as bitlines, data lines, or sense lines) and access lines (which may also be referred to as wordlines). The sense lines may conductively interconnect memory cells along columns of the array, and the access lines may conductively interconnect memory cells along rows of the array. Each memory cell may be uniquely addressed through the combination of a sense line and an access line.

Memory cells may be volatile, semi-volatile, or non-volatile. Non-volatile memory cells can store data for extended periods of time in the absence of power. Non-volatile memory is conventionally specified to be memory having a retention time of at least about 10 years. Volatile memory dissipates and is therefore refreshed/rewritten to maintain data storage. Volatile memory may have a retention time of milliseconds or less. Regardless, memory cells are configured to retain or store memory in at least two different selectable states. In a binary system, the states are considered as either a “0” or a “1”. In other systems, at least some individual memory cells may be configured to store more than two levels or states of information.

A field effect transistor is one type of electronic component that may be used in a memory cell. These transistors comprise a pair of conductive source/drain regions having a semiconductive channel region there-between. A conductive gate is adjacent the channel region and separated there-from by a thin gate insulator. Application of a suitable voltage to the gate allows current to flow from one of the source/drain regions to the other through the channel region. When the voltage is removed from the gate, current is largely prevented from flowing through the channel region. Field effect transistors may also include additional structure, for example a reversibly programmable charge-storage region as part of the gate construction between the gate insulator and the conductive gate.

Flash memory is one type of memory and has numerous uses in modern computers and devices. For instance, modern personal computers may have BIOS stored on a flash memory chip. As another example, it is becoming increasingly common for computers and other devices to utilize flash memory in solid state drives to replace conventional hard drives. As yet another example, flash memory is popular in wireless electronic devices because it enables manufacturers to support new communication protocols as they become standardized, and to provide the ability to remotely upgrade the devices for enhanced features.

NAND may be a basic architecture of integrated flash memory.

A NAND cell unit comprises at least one selecting device coupled in series to a serial combination of memory cells (with the serial combination commonly being referred to as a NAND string). NAND architecture may be configured in a three-dimensional arrangement comprising vertically-stacked memory cells individually comprising a reversibly programmable vertical transistor. Control or other circuitry may be formed below the vertically-stacked memory cells. Other volatile or non-volatile memory array architectures may also comprise vertically-stacked memory cells that individually comprise a transistor.

Memory arrays may be arranged in memory pages, memory blocks and partial blocks (e.g., sub-blocks), and memory planes, for example as shown and described in any of U.S. Patent Application Publication Nos. 2015/0228651, 2016/0267984, and 2017/0140833. The memory blocks may at least in part define longitudinal outlines of individual wordlines in individual wordline tiers of vertically-stacked memory cells. Connections to these wordlines may occur in a so-called “stair-step structure” at an end or edge of an array of the vertically-stacked memory cells. The stair-step structure includes individual “stairs” (alternately termed “steps” or “stair-steps”) that define contact regions of the individual wordlines upon which elevationally-extending conductive vias contact to provide electrical access to the wordlines.

1 91 FIGS.- Embodiments of the invention encompass methods used in forming integrated circuitry, for example memory circuitry comprising a memory array, for example an array of NAND or other memory cells (e.g., integrated-circuitry components) that may have at least some peripheral control circuitry under the array (e.g., CMOS-under-array). Alternately, and by way of examples only, peripheral control circuitry may be above the array or to a side of the array. Embodiments of the invention encompass “gate-last” or “replacement-gate” processing, so-called “gate-first” processing, and other processing whether existing or future-developed independent of when transistor gates are formed. Embodiments of the invention also encompass integrated circuitry such as that comprising a memory array comprising strings of memory cells (e.g., NAND architecture) independent of method of manufacture. Some example embodiments are described with reference to.

1 4 FIGS.- 1 4 FIGS.- 10 12 10 12 show an example constructionwith an arrayin which strings of memory cells will be formed. Example constructionmay include a lowest base substrate (not shown) having any one or more of conductive/conductor/conducting, semiconductive/semiconductor/semiconducting, or insulative/insulator/insulating (i.e., electrically herein) materials. Various materials may be formed above the base substrate. Materials may be aside, elevationally inward, or elevationally outward of thedepicted materials. For example, other partially or wholly fabricated components of integrated circuitry may be provided somewhere above, about, or within a base substrate. Control and/or other peripheral circuitry for operating components within an array (e.g., array) of elevationally-extending strings of memory cells may also be fabricated and may or may not be wholly or partially within an array or sub-array. Further, multiple sub-arrays may also be fabricated and operated independently, in tandem, or otherwise relative one another. In this document, a “sub-array” may also be considered as an array.

10 16 17 16 12 18 22 20 16 20 22 20 20 22 20 22 18 20 22 16 18 22 22 16 22 22 20 22 22 20 20 20 24 22 26 x Constructioncomprises a conductor tiercomprising conductor material(e.g., WSiunder conductively-doped polysilicon). Conductor tiermay comprise part of control circuitry (e.g., peripheral-under-array circuitry and/or a common source line or plate) used to control read and write access to the transistors and/or memory cells in array. A stackcomprising vertically-alternating first/conductive tiersand second/insulative tiershas been formed above conductor tier. Example thickness for each of tiersandis 20 to 60 nanometers. The example uppermost tiermay be thicker/thickest compared to one or more other tiersand/or. Only a small number of tiersandis shown, with more likely stackcomprising dozens, a hundred or more, etc. of tiersand. Other circuitry that may or may not be part of peripheral and/or control circuitry may be between conductor tierand stack. For example, multiple vertically-alternating tiers of conductive material and insulative material of such circuitry may be below a lowest of the conductive tiersand/or above an uppermost of the conductive tiers. For example, one or more select-gate tiers (not shown) may be between conductor tierand the lowest conductive tier. Conductive tiersmay not be conductive at this point of processing, for example if “gate-last”/“replacement gate”, and insulative tiersmay not be insulative at this point of processing (but will be at least in a finished-circuitry construction). Regardless, in some embodiments conductive tiersare referred to as first tiersand insulative tiersare referred to as second tiers, and which are of different compositions relative one another. Example insulative/second tierscomprise insulative material(e.g., silicon dioxide and/or other material that may be of one or more composition(s)). Example conductive/first tierscomprise sacrificial material(e.g., silicon nitride) in the example gate-last processing. Such would comprise conductive material (not shown) in so-called gate-first processing.

16 18 15 77 17 16 In one embodiment, between conductor tierand stackis a tier comprising sacrificial etch-stop material(e.g., metal material) and sacrificial material(e.g., polysilicon), the latter of which may be removed later and substituted with conductive material if forming lateral connection to sidewalls of channel material for directly electrically coupling such to conductor materialof conductor tier.

5 6 FIGS.and 7 FIG. 60 18 15 13 15 Referring to, horizontally-elongated trench openingshave been formed through stackto sacrificial etch-stop material, leaving patterned sub-stacksthere-between.shows removal of sacrificial etch-stop material(such thereby no longer being shown).

8 10 FIGS.- 11 12 FIGS.and 26 13 24 24 20 26 Referring to, sacrificial materialhas been transversely recessed relative to opposing sidewalls of sub-stacks(e.g., using phosphoric acid when such material is silicon nitride and insulative materialis silicon dioxide).show thinning of insulative materialof insulative tiersselectively relative to sacrificial material(e.g., using HF per the above compositions for 24 and 26).

13 14 FIGS.and 30 13 32 32 Referring to, a blocking insulator(e.g., charge-blocking material) has been formed on opposite sides of sub-stacks, followed by forming of storage material(e.g., charge-storage material). Example blocking insulators include one or more of silicon hafnium oxide and silicon dioxide. Storage materialmay be floating-gate material, such as doped or undoped silicon or charge-trapping material such as silicon nitride, metal dots, quantum dots, or nano dots.

15 16 FIGS.and 17 20 FIGS.- 32 13 30 24 13 34 36 61 61 68 36 30 32 34 36 61 37 Referring to, storage materialhas been transversely etched back relative to sidewalls of sub-stacks, followed by removing blocking insulatorfrom such sidewalls, and possible slight transverse thinning of insulative materialto ideally make sub-stacksto again have planar opposing sidewalls as shown.show deposition of a tunnel insulator(e.g., charge-passage material; e.g., a band gap-engineered structure having nitrogen-containing material [e.g., silicon nitride] sandwiched between two insulator oxides [e.g., silicon dioxide]), channel material(e.g., undoped or appropriately-doped crystalline semiconductor material, such as one or more of silicon, germanium, and so-called III/V semiconductor materials [e.g., GaAs, InP, GaP, and GaN]), and an oxidation-restricting material(e.g., silicon nitride). Materialmay be used to preclude or at least reduce oxidation of transverse sidesof channel material(by covering such sides as shown), if such oxidation is conducted, in subsequent processing as will be described below. Materials,,,,, and other material(s) (including lesser subsets thereof) are collectively shown as and only designated as materialin some figures due to scale.

21 29 62 60 13 62 63 60 61 36 34 32 30 26 61 36 34 32 30 26 62 5 FIG. 30 38 FIGS.- 39 47 FIGS.- Referring-, sacrificial masking material(e.g., spin-on-carbon) has been deposited to over-fill trench openingsand cover sub-stacks. Then, sacrificial masking materialhas been patterned as shown to form trench openingsthere-through and that are horizontally-elongated orthogonal to the horizontal-elongated direction of trench openingsin.show etching (e.g., wet) of oxidation-restricting material, channel material, tunnel insulator, and storage material.show subsequent etching of blocking insulator(e.g., wet or dry) to expose sacrificial material. The artisan is capable of selecting various anisotropic and/or isotropic etching chemistries to achieve the depicted profile depending on compositions of materials,,,, and. Transverse etching of sacrificial materialmay be additionally conducted if desired (not shown). Masking material(not shown) has been removed (e.g., by ashing if such is carbon).

53 53 26 22 20 18 10 64 26 22 53 53 The above processing is but one example of forming a first set A of horizontally-spaced pairsA of channel-material strings(so spaced by material) that extend through first tiersand second tiersof stack. In one such embodiment and as shown, constructioncomprises linesof sacrificial material. Such are individually in individual of first tiersand individually extend horizontally through (e.g., through the middle/center of) horizontally-spaced pairsA of first set A between channel-material stringsin individual of horizontally-spaced pairs of such first set A.

48 49 FIGS.and 41 47 FIGS.and 66 53 36 53 67 53 61 36 68 36 53 67 53 Referring to(positionally corresponding to, respectively), and in one embodiment, lateral sidewallsof channel-material stringsof first set A have been oxidized. In one such embodiment, channel materialof channel-material stringscomprises silicon and such oxidizing forms a vertically-continuous massof silicon dioxide along such lateral sidewalls of channel-material stringsof first set A. Oxidation-restricting material, when present being transversely aside channel materialbefore forming of first set A, restricts oxidation of transverse sidesof channel materialof channel-material stringsduring such oxidizing. Massesof silicon dioxide when formed may provide better isolation between immediately-laterally-adjacent channel-material strings one of which will be formed in one of the depicted gaps between channel-material-string pairsA (not-yet-shown).

50 52 FIGS.- 53 55 FIGS.- 30 32 30 32 32 Referring to, another layer of blocking insulatorand another layer of storage materialhave been deposited as shown. Such may or may not be of the same respective composition as the first-deposited blocking insulatorand storage material, but ideally are of the same respective composition.show exposed storage materialas having been transversely etched back (e.g., wet).

56 58 FIGS.- 34 36 34 36 Referring to, more tunnel insulatorand channel materialhave been formed. Such may be of the same or different respective composition as the first-deposited tunnel insulatorand first-deposited channel material, and ideally are of the same respective composition.

59 66 FIGS.- 21 29 FIG.- 62 60 13 62 70 63 Referring to, more sacrificial masking materialhas been deposited, again to over-fill trench openingsand cover sub-stacks. Then, sacrificial masking materialhas been patterned as shown to form trench openingsbetween where trench openingswere formed in.

67 73 FIGS.- 36 34 30 36 34 30 53 53 22 20 53 53 64 26 53 53 53 Referring to, exposed channel material, tunnel insulator, blocking insulator, and oxidation-barrier material (when present) have been etched back as shown. Alternately, only channel materialmay be etched back, with tunnel insulator, blocking insulator, and oxidation-barrier material remaining as such are insulative (not shown). Regardless, such has thereby formed a second set B of horizontally-spaced pairsB of channel-material stringsthat extend through first tiersand second tiers, with pairsA in first set A individually horizontally alternating with pairsB in second set B. In one such embodiment and as shown, linesof sacrificial materialindividually extend horizontally through horizontally-spaced pairsB of second set B between channel-material stringsin individual of horizontally-spaced pairsB of second set B.

74 91 FIGS.- 74 78 FIGS.- 74 75 FIGS.and 69 70 FIGS.and 79 80 FIGS.and 74 75 FIGS.and 36 53 13 24 22 20 19 24 36 36 53 show example subsequent/down-stream processing some of which is not particularly material to aspects of the invention. Referring to(positionally corresponding to, respectively), tops of channel materialin sets A and B have been patterned and etched to segment such into select gate drain (SGD) sides of channel-material strings. Thereafter, the illustrated void-space resulting therefrom and void-space between sub-stackshave been filled with an insulator (e.g.,) and planarized back as shown.(positionally corresponding to, respectively) show formation of more first tiersand more second tiersfor ultimate formation of conductive lines for SGD's, followed by formation of example structureshaving insulative materialsurrounded by more channel materialthat is directly against a respective top of channel materialof channel-material strings.

81 89 FIGS.- 40 18 58 77 42 36 18 16 26 48 26 48 29 53 53 53 53 53 26 48 22 48 26 48 3 4 x Referring to, horizontally-elongated trencheshave been formed through stack, forming memory blocks. This has been followed, by way of example only, by replacing of sacrificial materialwith conductive materialafter having exposed sidewalls of channel material(not shown) below stackfor making sidewall connection therewith and direct electrical coupling with conductor tier. Thereafter or before, sacrificial material(no longer shown) has been removed by etching (e.g., with HPO) and volume resulting from such removing has been filled with conductive material(e.g., conductive metal material). Accordingly, and by way of example only, sacrificial materialhas been replaced with conductive materialto form conductive control-gate linesthat individually extend horizontally through horizontally-spaced pairsA andB between channel-material stringsin individual horizontally-spaced pairsA andB in each of first set A and second set B. In one embodiment, after removing sacrificial materialsand prior to the forming conductive material, first tiersmay be lined with an insulating material (e.g., AlOand not shown), with conductive materialbeing formed thereover (e.g., the replacing of sacrificial materialnot being entirely with conductive material).

49 56 34 32 34 22 53 32 69 53 34 34 22 20 49 56 30 20 89 FIG. 86 87 FIGS.and The example depicted processing has formed stringsof memory cells. In one embodiment and as shown, such comprise tunnel insulatorand storage material, with tunnel insulatorin second set B in first tiersextending from between individual of channel-material stringsand storage materialto be over laterally-opposing sides() of individual channel-material strings. In one such embodiment and as shown, tunnel insulatordoes not so-extend in first set A. In one such embodiment, tunnel insulatorextends through first tiersand second tiers. Regardless, in one embodiment, stringsof memory cellscomprise blocking insulator, with such blocking insulator not extending through second tiers(such being vertically isolated/separated from extending-through as shown in).

56 48 52 56 52 29 89 FIG. 86 88 FIGS.- 89 FIG. Approximate locations of transistors and/or memory cellsare indicated with a bracket inand some with dashed outlines in. Conductive materialmay be considered as having control-gate regions() of individual transistors and/or memory cells. Control-gate regionsin the depicted embodiment comprise individual portions of individual conductive lines.

30 32 52 30 32 32 48 30 48 30 30 32 30 A charge-blocking region (e.g., charge-blocking material) is between storage materialand individual control-gate regions. A charge block may have the following functions in a memory cell: In a program mode, the charge block may prevent charge carriers from passing out of the storage material (e.g., floating-gate material, charge-trapping material, etc.) toward the control gate, and in an erase mode the charge block may prevent charge carriers from flowing into the storage material from the control gate. Accordingly, a charge block may function to block charge migration between the control-gate region and the storage material of individual memory cells. An example charge-blocking region as shown comprises insulator material. By way of further examples, a charge-blocking region may comprise a laterally outer portion of the storage material (e.g., material) where such storage material is insulative (e.g., in the absence of any different-composition material between an insulative storage materialand conductive material). Regardless, as an additional example, an interface of a storage material and conductive material of a control gate may be sufficient to function as a charge-blocking region in the absence of any separate-composition-insulator material. Further, an interface of conductive materialwith material(when present) in combination with insulator materialmay together function as a charge-blocking region, and as alternately or additionally may a laterally-outer region of an insulative storage material (e.g., a silicon nitride material). An example materialis one or more of silicon hafnium oxide and silicon dioxide.

90 91 FIGS.and 84 85 FIGS.and 95 96 24 97 53 36 19 97 (positionally corresponding to, respectively) show example downstream processing wherein trenches(only one being shown) have been formed to form SGD sub-blocks, followed by forming of more insulative materialand conductive viasthat individually directly electrically couple to individual channel-material stringsthrough channel materialof structures. Digitlines (not shown) may be subsequently formed that directly electrically couple to multiple of conductive vias.

Any other attribute(s) or aspect(s) as shown and/or described herein with respect to other embodiments may be used with respect to the above embodiments.

56 32 18 22 20 71 71 71 71 In one embodiment, a method used in forming memory circuitry comprising memory cells (e.g.,) that individually comprise storage material (e.g.,) comprises forming a stack (e.g.,) comprising vertically-alternating first tiers (e.g.,) and second tiers (e.g.,). The first tiers are conductive and the second tiers are insulative at least in a finished-circuitry construction. A first set (e.g., A) of horizontally-spaced pairs (e.g.,A) of masses (e.g.,) of the storage material is formed. After forming the first set, a second set (e.g., B) of horizontally-spaced pairs (e.g.,B) of masses (e.g.,) of the storage material is formed. The pairs in the first set individually horizontally alternate with the pairs in the second set.

30 29 53 72 73 89 FIG. In one embodiment, the memory cells comprise blocking insulator (e.g.,), part of a control-gate line (e.g.,), and part of a channel-material string (e.g.,). The blocking insulator in the first tiers extends from between the part of the control-gate line and the storage material to be over opposing lateral sides (e.g.,) of each of storage-material masses, the tunnel insulator, and the part of the channel-material string on both transverse sides (e.g.,) of the part of the control-gate line ().

24 30 30 In one embodiment, the storage-material masses of the first and second sets are individually isolated horizontally and vertically from immediately-adjacent of the storage-material masses by insulative material (e.g.,,). In one such embodiment, the memory cells comprise blocking insulator (e.g.,), with the insulative material in the horizontal isolation being the blocking insulator.

Any other attribute(s) or aspect(s) as shown and/or described herein with respect to other embodiments may be used.

56 32 18 22 20 71 71 32 64 26 88 71 71 32 48 29 47 88 FIGS.and 46 47 FIGS.and 73 FIGS. In one embodiment, a method used in forming memory circuitry comprising memory cells (e.g.,) that individually comprise storage material (e.g.,) comprises forming a stack (e.g.,) comprising vertically-alternating first tiers (e.g.,) and second tiers (e.g.,.) The first tiers are conductive and the second tiers are insulative at least in a finished-circuitry construction. A first set (e.g., A in) of horizontally-spaced pairs (e.g.,A) of masses (e.g.,) of the storage material (e.g.,) is formed (). Lines (e.g.,) of sacrificial material (e.g.,) are in individual of the first tiers and individually extend horizontally through the horizontally-spaced pairs of the first set between the storage-material masses in individual of the horizontally-spaced pairs of the first set. After forming the first set, a second set (e.g., B inand) of horizontally-spaced pairs (e.g.,B) of masses (e.g.,) of storage material (e.g.,) is formed. The pairs in the first set individually horizontally alternate with the pairs in the second set. The lines of sacrificial material individually extend horizontally through the horizontally-spaced pairs of the second set between the storage-material masses in individual of the horizontally-spaced pairs of the second set. After forming the first and second sets, the sacrificial material is replaced with conductive material (e.g.,) to form conductive control-gate lines (e.g.,) that individually extend horizontally through the horizontally-spaced pairs between the storage-material masses in the individual horizontally-spaced pairs in each of the first and second sets.

Any other attribute(s) or aspect(s) as shown and/or described herein with respect to other embodiments may be used.

Alternate embodiment constructions may result from method embodiments described above, or otherwise. Regardless, embodiments of the invention encompass circuitry independent of method of manufacture. Nevertheless, such circuitry arrays may have any of the attributes as described herein in method embodiments. Likewise, the above-described method embodiments may incorporate, form, and/or have any of the attributes described with respect to device embodiments.

49 56 18 20 22 53 53 29 34 30 32 69 In one embodiment, a memory array comprising strings (e.g.,) of memory cells (e.g.,) comprises a stack (e.g.,) comprising vertically-alternating insulative tiers (e.g.,) and conductive tiers (e.g.,). Horizontally-spaced pairs (e.g.,*, an* being used as a suffix to be inclusive of all such same-numerically-designated structures or portions thereof that may or may not have other suffixes) of channel-material strings (e.g.,) extend through the insulative tiers and the conductive tiers. Control-gate lines (e.g.,) are in individual of the conductive tiers and individually extend horizontally through the horizontally-spaced pairs between the channel-material strings in individual of the horizontally-spaced pairs. The memory cells individually comprise part of one of the channel-material strings in one of the pairs in one of the conductive tiers, part of one of the control-gate lines in the one pair in the one conductive tier, tunnel insulator (e.g.,) in the one conductive tier that is adjacent the part of the one channel-material string in the one pair in the one conductive tier, blocking insulator (e.g.,) in the one conductive tier that is adjacent the part of the one control-gate line in the one pair in the one conductive tier, and storage material (e.g.,) in the one conductive tier that is between the tunnel insulator and the blocking insulator. The tunnel insulator in the one conductive tier extends from between the part of the one channel-material string in the one pair and the storage material to be over opposing lateral sides (e.g.,) of the one channel-material string in the one pair.

67 In one embodiment, the horizontally-spaced pairs of channel-material strings are in first (e.g., A) and second (e.g., B) sets wherein the pairs in the first set individually horizontally alternate with the pairs in the second set. Only one of the first and second sets have the tunnel insulator extending to be over the opposing lateral sides of the one channel-material string. In one such embodiment, in the other of the first and second sets, the one channel-material string in the one pair in the one conductive tier and the storage material in the one conductive tier have opposing coplanar lateral sides (e.g., as would occur if vertically-continuous masseswere not present, and not shown). In one embodiment, in the one of the first and second sets, the one channel-material string in the one pair in the one conductive tier and the storage material in the one conductive tier do not have coplanar lateral sides.

30 In one embodiment, the tunnel insulator extends through the insulative tiers and the conductive tiers, in one embodiment the blocking insulator does not extend through the insulative tiers, and in one embodiment the storage material does not extend through the insulative tiers. In one embodiment, the storage material in immediately adjacent of the memory cells horizontally along opposing transverse sides of the one control-gate line are horizontally separated from one another by insulative material (e.g.,) that is of different composition from that of the storage material.

Any other attribute(s) or aspect(s) as shown and/or described herein with respect to other embodiments may be used.

49 56 18 20 22 53 53 29 34 30 32 30 In one embodiment, a memory array comprising strings (e.g.,) of memory cells (e.g.,) comprises a stack (e.g.,) comprising vertically-alternating insulative tiers (e.g.,) and conductive tiers (e.g.,). Horizontally-spaced pairs (e.g.,*) of channel-material strings (e.g.,) extend through the insulative tiers and the conductive tiers. Control-gate lines (e.g.,) are in individual of the conductive tiers and individually extend horizontally through the horizontally-spaced pairs between the channel-material strings in individual of the horizontally-spaced pairs. The memory cells individually comprise part of one of the channel-material strings in one of the pairs in one of the conductive tiers, part of one of the control-gate lines in the one pair in the one conductive tier, tunnel insulator (e.g.,) in the one conductive tier that is adjacent the part of the one channel-material string in the one pair in the one conductive tier, blocking insulator (e.g.,) in the one conductive tier that is adjacent the part of the one control-gate line in the one pair in the one conductive tier, and storage material (e.g.,) in the one conductive tier that is between the tunnel insulator and the blocking insulator. The storage material in immediately adjacent of the memory cells horizontally along opposing transverse sides of the one control-gate line are horizontally separated from one another by insulative material (e.g.,) that is of different composition from that of the storage material.

67 In one embodiment, the blocking insulator is directly above and directly below the storage material. In one embodiment, the one channel-material string in the one pair in the one conductive tier and the storage material in the one conductive tier have opposing coplanar lateral sides (e.g., as would occur if vertically-continuous masseswere not present, and not shown). In one embodiment, the one channel-material string in the one pair in the one conductive tier and the storage material in the one conductive tier do not have coplanar lateral sides.

Any other attribute(s) or aspect(s) as shown and/or described herein with respect to other embodiments may be used.

49 56 18 20 22 53 53 29 34 30 32 73 30 In one embodiment, a memory array comprising strings (e.g.,) of memory cells (e.g.,) comprises a stack (e.g.,) comprising vertically-alternating insulative tiers (e.g.,) and conductive tiers (e.g.,). Horizontally-spaced pairs (e.g.,*) of channel-material strings (e.g.,) extend through the insulative tiers and the conductive tiers. Control-gate lines (e.g.,) are in individual of the conductive tiers and individually extend horizontally through the horizontally-spaced pairs between the channel-material strings in individual of the horizontally-spaced pairs. The memory cells individually comprise part of one of the channel-material strings in one of the pairs in one of the conductive tiers, part of one of the control-gate lines in the one pair in the one conductive tier, tunnel insulator (e.g.,) in the one conductive tier that is adjacent the part of the one channel-material string in the one pair in the one conductive tier, blocking insulator (e.g.,) in the one conductive tier that is adjacent the part of the one control-gate line in the one pair in the one conductive tier, and storage material (e.g.,) in the one conductive tier that is between the tunnel insulator and the blocking insulator. The tunnel insulator in immediately-adjacent of the memory cells horizontally along opposing transverse sides (e.g.,) of the one control-gate line are horizontally separated from one another by insulative material (e.g.,) that is of different composition from that of the tunnel insulator.

In one embodiment, the insulative material comprises a transverse extension of the blocking insulator that is between the part of the one control-gate line in the one pair and the storage material. In one embodiment, the tunnel insulator extends through the insulative tiers and the conductive tiers.

Any other attribute(s) or aspect(s) as shown and/or described herein with respect to other embodiments may be used.

49 56 18 20 22 53 53 29 34 30 32 In one embodiment, a memory array comprising strings (e.g.,) of memory cells (e.g.,) comprises a stack (e.g.,) comprising vertically-alternating insulative tiers (e.g.,) and conductive tiers (e.g.,). Horizontally-spaced pairs (e.g.,*) of channel-material strings (e.g.,) extend through the insulative tiers and the conductive tiers. Control-gate lines (e.g.,) are in individual of the conductive tiers and individually extend horizontally through the horizontally-spaced pairs between the channel-material strings in individual of the horizontally-spaced pairs. The memory cells individually comprise part of one of the channel-material strings in one of the pairs in one of the conductive tiers, part of one of the control-gate lines in the one pair in the one conductive tier, tunnel insulator (e.g.,) in the one conductive tier that is adjacent the part of the one channel-material string in the one pair in the one conductive tier, blocking insulator (e.g.,) in the one conductive tier that is adjacent the part of the one control-gate line in the one pair in the one conductive tier, and storage material (e.g.,) in the one conductive tier that is between the tunnel insulator and the blocking insulator. The blocking insulator in the one conductive tier extends from between the part of the one control-gate line in the one pair and the storage material to be over opposing lateral sides of each of the storage material, the tunnel insulator, and the one channel-material string in the one pair on both transverse sides of the one control-gate line.

In one embodiment, each of the respective opposing lateral sides of the storage material and the tunnel insulator are coplanar. In one embodiment, the blocking insulator is directly above and directly below the storage material.

Any other attribute(s) or aspect(s) as shown and/or described herein with respect to other embodiments may be used.

In some prior methods and constructions, small circular openings in which channel-material strings will be received are etched completely through the stack. Further, gates of memory cells comprising such channel-material strings typically completely circumferentially surround such channel-material strings (gate-all-around). In some embodiments of the invention compared to such prior methods, etching through the stack to form openings in which channel-material strings are received may be easier. In some embodiments of the invention compared to such prior constructions, greater memory cell density may be achieved in the absence of gate-all-around. In some embodiments of the invention compared to such prior constructions, better lateral memory cell isolation between immediately-laterally-adjacent memory cells and better memory cell performance may be achieved due to better storage material separation between immediately-laterally-adjacent memory cells.

The memory circuitry described herein (e.g., conductive vias thereof) may connect with circuitry that is on either the top or the bottom (i.e., either z-axis side) of the stack regardless of orientation of the construction in three-dimensional space and which is not material to aspects of the inventions disclosed herein. For example, and by way of example only, the conductive vias may connect with peripheral control circuitry that is beneath the stack with respect to the orientation shown in the drawings. As an alternate example, and by way of example only, the conductive vias may connect with peripheral control circuitry that is above the stack with respect to the shown orientation, for example to another substrate having such circuitry and that is bonded with the top of the stack with respect to the shown orientation. In such alternate example, the construction may be inverted from the shown orientation and then bonded with the other substrate. Further, in such alternate example, source lines or plates may be fabricated relative to the bottom of the stack with respect to the shown orientation but inverted therefrom during processing. Such source lines or plates may connect with conductive vias that extend through the stack to the substrate bonded with the other side that has such peripheral control circuitry. Regardless, constructions as shown and described herein may be processed, packaged, and/or mounted in any three-dimensional spatial orientation.

The above processing(s) or construction(s) may be considered as being relative to an array of components formed as or within a single stack or single deck of such components above or as part of an underlying base substrate (albeit, the single stack/deck may have multiple tiers). Control and/or other peripheral circuitry for operating or accessing such components within an array may also be formed anywhere as part of the finished construction, and in some embodiments may be under the array (e.g., CMOS under-array). Regardless, one or more additional such stack(s)/deck(s) may be provided or fabricated above and/or below that shown in the figures or described above. Further, the array(s) of components may be the same or different relative one another in different stacks/decks and different stacks/decks may be of the same thickness or of different thicknesses relative one another. Intervening structure may be provided between immediately-vertically-adjacent stacks/decks (e.g., additional circuitry and/or dielectric layers). Also, different stacks/decks may be electrically coupled relative one another. The multiple stacks/decks may be fabricated separately and sequentially (e.g., one atop another), or two or more stacks/decks may be fabricated at essentially the same time.

The assemblies and structures discussed above may be used in integrated circuits/circuitry and may be incorporated into electronic systems. Such electronic systems may be used in, for example, memory modules, device drivers, power modules, communication modules, modems, processor and application-specific modules, and may include multilayer, multichip modules. The electronic systems may be any of a broad range of systems, such as, for example, cameras, wireless devices, displays, chip sets, set top boxes, games, lighting, vehicles, clocks, televisions, cell phones, personal computers, automobiles, industrial control systems, aircraft, etc.

In this document unless otherwise indicated, “elevational”, “higher”, “upper”, “lower”, “top”, “atop”, “bottom”, “above”, “below”, “under”, “beneath”, “up”, and “down” are generally with reference to the vertical direction. “Horizontal” refers to a general direction (i.e., within 10 degrees) along a primary substrate surface and may be relative to which the substrate is processed during fabrication and as shown in drawings (if any) herein, and vertical is a direction generally orthogonal thereto. Reference to “exactly horizontal” is the direction along the primary substrate surface (i.e., no degrees there-from) and may be relative to which the substrate is processed during fabrication. Further, “vertical” and “horizontal” as used herein are generally perpendicular directions relative one another and independent of orientation of the substrate in three-dimensional space during fabrication and/or in a finished construction. Additionally, “elevationally-extending”and “extend (ing) elevationally” refer to a direction that is angled away by at least 45° from exactly horizontal. Further, “extend (ing) elevationally”, “elevationally-extending”, “extend (ing) horizontally”, “horizontally-extending” and the like with respect to a field effect transistor are with reference to orientation of the transistor's channel length along which current flows in operation between the source/drain regions. For bipolar junction transistors, “extend (ing) elevationally” “elevationally-extending”, “extend (ing) horizontally”, “horizontally-extending” and the like, are with reference to orientation of the base length along which current flows in operation between the emitter and collector. In some embodiments, any component, feature, and/or region that extends elevationally extends vertically or within 10° of vertical.

Further, “directly above”, “directly below”, and “directly under” require at least some lateral overlap (i.e., horizontally) of two stated regions/materials/components relative one another. Also, use of “above” not preceded by “directly” only requires that some portion of the stated region/material/component that is above the other be elevationally outward of the other (i.e., independent of whether there is any lateral overlap of the two stated regions/materials/components). Analogously, use of “below” and “under” not preceded by “directly” only requires that some portion of the stated region/material/component that is below/under the other be elevationally inward of the other (i.e., independent of whether there is any lateral overlap of the two stated regions/materials/components).

Any of the materials, regions, and structures described herein may be homogenous or non-homogenous, and regardless may be continuous or discontinuous over any material which such overlie. Where one or more example composition(s) is/are provided for any material, that material may comprise, consist essentially of, or consist of such one or more composition(s). Further, unless otherwise stated, each material may be formed using any suitable existing or future-developed technique, with atomic layer deposition, chemical vapor deposition, physical vapor deposition, epitaxial growth, diffusion doping, and ion implanting being examples.

Additionally, “thickness” by itself (no preceding directional adjective) is defined as the mean straight-line distance through a given material or region perpendicularly from a closest surface of an immediately-adjacent material of different composition or of an immediately-adjacent region. Additionally, the various materials or regions described herein may be of substantially constant thickness or of variable thicknesses. If of variable thickness, thickness refers to average thickness unless otherwise indicated, and such material or region will have some minimum thickness and some maximum thickness due to the thickness being variable. As used herein, “different composition” only requires those portions of two stated materials or regions that may be directly against one another to be chemically and/or physically different, for example if such materials or regions are not homogenous. If the two stated materials or regions are not directly against one another, “different composition” only requires that those portions of the two stated materials or regions that are closest to one another be chemically and/or physically different if such materials or regions are not homogenous. In this document, a material, region, or structure is “directly against” another when there is at least some physical touching contact of the stated materials, regions, or structures relative one another. In contrast, “over”, “on”, “adjacent”, “along”, and “against” not preceded by “directly” encompass “directly against” as well as construction where intervening material(s), region(s), or structure(s) result(s) in no physical touching contact of the stated materials, regions, or structures relative one another.

Herein, regions-materials-components are “electrically coupled” relative one another if in normal operation electric current is capable of continuously flowing from one to the other and does so predominately by movement of subatomic positive and/or negative charges when such are sufficiently generated. Another electronic component may be between and electrically coupled to the regions-materials-components. In contrast, when regions-materials-components are referred to as being “directly electrically coupled”, no intervening electronic component (e.g., no diode, transistor, resistor, transducer, switch, fuse, etc.) is between the directly electrically coupled regions-materials-components.

Any use of “row” and “column” in this document is for convenience in distinguishing one series or orientation of features from another series or orientation of features and along which components have been or may be formed. “Row” and “column” are used synonymously with respect to any series of regions, components, and/or features independent of function. Regardless, the rows may be straight and/or curved and/or parallel and/or not parallel relative one another, as may be the columns. Further, the rows and columns may intersect relative one another at 90° or at one or more other angles (i.e., other than the straight angle).

The composition of any of the conductive/conductor/conducting materials herein may be conductive metal material and/or conductively-doped semiconductive/semiconductor/semiconducting material. “Metal material” is any one or combination of an elemental metal, any mixture or alloy of two or more elemental metals, and any one or more metallic compound(s).

Herein, any use of “selective” as to etch, etching, removing, removal, depositing, forming, and/or formation is such an act of one stated material relative to another stated material(s) so acted upon at a rate of at least 2:1 by volume. Further, any use of selectively depositing, selectively growing, or selectively forming is depositing, growing, or forming one material relative to another stated material or materials at a rate of at least 2:1 by volume for at least the first 75 Angstroms of depositing, growing, or forming.

Unless otherwise indicated, use of “or” herein encompasses either and both.

In some embodiments, a method used in forming memory circuitry comprising strings of memory cells comprising channel-material strings comprises forming a stack comprising vertically-alternating first tiers and second tiers. The first tiers are conductive and the second tiers are insulative at least in a finished-circuitry construction. A first set of horizontally-spaced pairs of channel-material strings are formed to extend through the first tiers and the second tiers. After forming the first set, a second set of horizontally-spaced pairs of channel-material strings is formed to extend through the first tiers and the second tiers. The pairs in the first set individually horizontally alternate with the pairs in the second set.

In some embodiments, a method used in forming memory circuitry comprising memory cells that individually comprise storage material comprises forming a stack comprising vertically-alternating first tiers and second tiers. The first tiers are conductive and the second tiers are insulative at least in a finished-circuitry construction. A first set of horizontally-spaced pairs of masses of the storage material is formed. After forming the first set, a second set of horizontally-spaced pairs of masses of the storage material is formed. The pairs in the first set individually horizontally alternate with the pairs in the second set.

In some embodiments, a method used in forming memory circuitry comprising strings of memory cells comprising channel-material strings comprises forming a stack comprising vertically-alternating first tiers and second tiers. The first tiers are conductive and the second tiers are insulative at least in a finished-circuitry construction. A first set of horizontally-spaced pairs of channel-material strings is formed to extend through the first tiers and the second tiers. Lines of sacrificial material are in individual of the first tiers and individually extend horizontally through the horizontally-spaced pairs of the first set between the channel-material strings in individual of the horizontally-spaced pairs of the first set. After forming the first set, a second set of horizontally-spaced pairs of channel-material strings is formed to extend through the first tiers and the second tiers. The pairs in the first set individually horizontally alternate with the pairs in the second set. The lines of sacrificial material individually extend horizontally through the horizontally-spaced pairs of the second set between the channel-material strings in individual of the horizontally-spaced pairs of the second set. After forming the first and second sets, the sacrificial material is replaced with conductive material to form conductive control-gate lines that individually extend horizontally through the horizontally-spaced pairs between the channel-material strings in the individual horizontally-spaced pairs in each of the first and second sets.

In some embodiments, a method used in forming memory circuitry comprising memory cells that individually comprise storage material comprises forming a stack comprising vertically-alternating first tiers and second tiers. The first tiers are conductive and the second tiers are insulative at least in a finished-circuitry construction. A first set of horizontally-spaced pairs of masses of the storage material is formed. Lines of sacrificial material are in individual of the first tiers and individually extend horizontally through the horizontally-spaced pairs of the first set between the storage-material masses in individual of the horizontally-spaced pairs of the first set. After forming the first set, a second set of horizontally-spaced pairs of masses of the storage material is formed. The pairs in the first set individually horizontally alternate with the pairs in the second set. The lines of sacrificial material individually extend horizontally through the horizontally-spaced pairs of the second set between the storage-material masses in individual of the horizontally-spaced pairs of the second set. After forming the first and second sets, the sacrificial material is replaced with conductive material to form conductive control-gate lines that individually extend horizontally through the horizontally-spaced pairs between the storage-material masses in the individual horizontally-spaced pairs in each of the first and second sets.

In some embodiments, a memory array comprising strings of memory cells comprises a stack comprising vertically-alternating insulative tiers and conductive tiers. Horizontally-spaced pairs of channel-material strings extend through the insulative tiers and the conductive tiers. Control-gate lines are in individual of the conductive tiers and individually extend horizontally through the horizontally-spaced pairs between the channel-material strings in individual of the horizontally-spaced pairs. The memory cells individually comprise part of one of the channel-material strings in one of the pairs in one of the conductive tiers, part of one of the control-gate lines in the one pair in the one conductive tier, tunnel insulator in the one conductive tier that is adjacent the part of the one channel-material string in the one pair in the one conductive tier, blocking insulator in the one conductive tier that is adjacent the part of the one control-gate line in the one pair in the one conductive tier, and storage material in the one conductive tier that is between the tunnel insulator and the blocking insulator. The tunnel insulator in the one conductive tier extends from between the part of the one channel-material string in the one pair and the storage material to be over opposing lateral sides of the one channel-material string in the one pair.

In some embodiments, a memory array comprising strings of memory cells comprises a stack comprising vertically-alternating insulative tiers and conductive tiers. Horizontally-spaced pairs of channel-material strings extend through the insulative tiers and the conductive tiers. Control-gate lines are in individual of the conductive tiers and individually extend horizontally through the horizontally-spaced pairs between the channel-material strings in individual of the horizontally-spaced pairs. The memory cells individually comprise part of one of the channel-material strings in one of the pairs in one of the conductive tiers, part of one of the control-gate lines in the one pair in the one conductive tier, tunnel insulator in the one conductive tier that is adjacent the part of the one channel-material string in the one pair in the one conductive tier, blocking insulator in the one conductive tier that is adjacent the part of the one control-gate line in the one pair in the one conductive tier, and storage material in the one conductive tier that is between the tunnel insulator and the blocking insulator. The storage material in immediately adjacent of the memory cells horizontally along opposing transverse sides of the one control-gate line are horizontally separated from one another by insulative material that is of different composition from that of the storage material.

In some embodiments, a memory array comprising strings of memory cells comprises a stack comprising vertically-alternating insulative tiers and conductive tiers. Horizontally-spaced pairs of channel-material strings extend through the insulative tiers and the conductive tiers. Control-gate lines are in individual of the conductive tiers and individually extend horizontally through the horizontally-spaced pairs between the channel-material strings in individual of the horizontally-spaced pairs. The memory cells individually comprise part of one of the channel-material strings in one of the pairs in one of the conductive tiers, part of one of the control-gate lines in the one pair in the one conductive tier, tunnel insulator in the one conductive tier that is adjacent the part of the one channel-material string in the one pair in the one conductive tier, blocking insulator in the one conductive tier that is adjacent the part of the one control-gate line in the one pair in the one conductive tier, and storage material in the one conductive tier that is between the tunnel insulator and the blocking insulator. The tunnel insulator in immediately-adjacent of the memory cells horizontally along opposing transverse sides of the one control-gate line are horizontally separated from one another by insulative material that is of different composition from that of the tunnel insulator.

In some embodiments, a memory array comprising strings of memory cells comprises a stack comprising vertically-alternating insulative tiers and conductive tiers. Horizontally-spaced pairs of channel-material strings extend through the insulative tiers and the conductive tiers. Control-gate lines are in individual of the conductive tiers and individually extend horizontally through the horizontally-spaced pairs between the channel-material strings in individual of the horizontally-spaced pairs. The memory cells individually comprise part of one of the channel-material strings in one of the pairs in one of the conductive tiers, part of one of the control-gate lines in the one pair in the one conductive tier, tunnel insulator in the one conductive tier that is adjacent the part of the one channel-material string in the one pair in the one conductive tier, blocking insulator in the one conductive tier that is adjacent the part of the one control-gate line in the one pair in the one conductive tier, and storage material in the one conductive tier that is between the tunnel insulator and the blocking insulator. The blocking insulator in the one conductive tier extends from between the part of the one control-gate line in the one pair and the storage material to be over opposing lateral sides of each of the storage material, the tunnel insulator, and the one channel-material string in the one pair on both transverse sides of the one control-gate line.

In some embodiments, a memory array comprising strings of memory cells comprises a stack comprising vertically-alternating insulative tiers and conductive tiers. Horizontally-spaced pairs of channel-material strings extend through the insulative tiers and the conductive tiers. Control-gate lines are in individual of the conductive tiers and individually extend horizontally through the horizontally-spaced pairs between the channel-material strings in individual of the horizontally-spaced pairs. The memory cells individually comprise part of one of the channel-material strings in one of the pairs in one of the conductive tiers, part of one of the control-gate lines in the one pair in the one conductive tier, tunnel insulator in the one conductive tier that is adjacent the part of the one channel-material string in the one pair in the one conductive tier, blocking insulator in the one conductive tier that is adjacent the part of the one control-gate line in the one pair in the one conductive tier, and storage material in the one conductive tier that is between the tunnel insulator and the blocking insulator. The tunnel insulator in the one conductive tier extends from between the part of the one channel-material string in the one pair and the storage material to be over opposing lateral sides of the one channel-material string in the one pair. The storage material in immediately adjacent of the memory cells horizontally along opposing transverse sides of the one control-gate line are horizontally separated from one another by insulative material that is of different composition from that of the storage material. The tunnel insulator in immediately-adjacent of the memory cells horizontally along the opposing transverse sides of the one control-gate line are horizontally separated from one another by insulative material that is of different composition from that of the tunnel insulator. The blocking insulator in the one conductive tier extends from between the part of the one control-gate line in the one pair and the storage material to be over opposing lateral sides of each of the storage material, the tunnel insulator, and the one channel-material string in the one pair on both transverse sides of the one control-gate line.

In compliance with the statute, the subject matter disclosed herein has been described in language more or less specific as to structural and methodical features. It is to be understood, however, that the claims are not limited to the specific features shown and described, since the means herein disclosed comprise example embodiments. The claims are thus to be afforded full scope as literally worded, and to be appropriately interpreted in accordance with the doctrine of equivalents.